Quick action under-arm insulator for field lines



2,817,700 QUICK ACTION UNDER-ARM INSULATOR FOR FIELD LINES I Filed Sept. 28, 1956 Dec. 24, 1957 v H, L. BOERLIN 2 Sheets-Sheet 1 INVENTOR. Hamfa L50erZz'7z A FOR/YE) Dec. 24, 1957 H. L. BOERLIN 2,317,700

QUICK ACTION UNDER-ARM INSULATOR FOR FIELD LINES Filed Sept. 28, 1956 2 Sheets-Sheet 2 nited States atent @fiice QUICK ACTION UNDER-ARM INSULATOR FOR FIELD LINES Harold L. Boerlin, Alexandria, Va.

Application September 28, 1956, Serial No. 612,897

4 Claims. (Cl. 174--154) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States for governmental purposes without the payment of any royalty thereon.

This invention relates to under-arm insulators of the general character illustrated in my copending application, Serial No. 380,629, filed September 16, 1953, and has for an object to improve the construction of such insulators with the purpose of enabling more rapid and facile operation of the device for the laying of pole-supported telegraph and telephone lines without requiring the workmen to climb the poles. A particular aim of the invention is to simplify the means for receiving and securing a line laid by the use of the invention, so that a rugged device is provided Which Will withstand rough usage in the field and may be more easily operated by a workman standing on the ground and using only a pike device.

A further aim of the invention is to provide such an insulator by which the securement of the wire will be positive and safe against accidental release. A further aim is to improve a linkage device by which clamping members are drawn together to compress an insulator about a wire laid in the device.

A further specific object is to improve the construction of a dead center lever and link construction by which clamping and line releasing action of the device is effected with fewer motions of the device and its users.

Another aim of the invention is to provide a novel function of the parts in the opening and wire-receiving action of the device.

Additional objects, advantages, and features of invention will be apparent or disclosed in the following description and accompanying drawings, wherein,

Fig. 1 is a perspective view of an embodiment of my invention in place upon a crossarm;

Fig. 2 is a front elevational view of the lower part of the device;

Fig. 3 is a side view of the device open;

Fig. 4 is a similar view with the device closed;

Fig. 5 is a cross-section on the line 5--5 of Fig. 2.

Fig. 6 is a view of one example of a pike or pole implement by which my insulator may be operated by a person on the ground, to lay a wire on field pole cross arms.

Referring more particularly to the drawings, there is illustrated a crossarm 10, upon which my insulator is installed, the insulator comprising a cast base piece having a shank 11 extended upwardly therefrom by which a clamping member is suspended below the crossarm. The shank may be formed with a bolt-like upper portion 12 extended through the crossarm and secured by a nut or the like, not shown. The shank is formed with a shoulder portion 13 set against the underside of the crossarm.

At its intermediate portion the base piece is formed with a horizontal semi-cylindrical channelled cross piece 14, and below the cross piece the body is extended to form a hinge leaf and knuckle 15. Hinged on the knuckle there is a T-shaped clamping member 16 the upper part 18 of which is a cross head shaped like the cross piece 14 and channelled to align with the latter when the clamping member is moved close to the channelled piece 14. The stem of the T-shaped member 16 consists of a hinge leaf and knuckle 17, and its upper or channelled part 18 may be termed the clamp.

Set between the channels of the crosspiece 14 and clamping member there is an elastic deformable rubber or other, generally cylindrical insulator proper 19, having a channel 20 extending longitudinally thereof, open at the upper side and of an extent permitting it to be closed by closing of the clamp member, as described. Its resilience and tendency to move to its open position will be utilized to effect parting movement of the clamp 18 and cross member as will appear.

The hinge piece 15 is formed with a stiffening rib 21 on which there is fulcrum-pivoted a bifurcated lever 22, the extremities of the arms of the lever being disposed on respective sides of the rib. A resilient wire link 23 generally U-shaped, has the extremities of its anns inturned and pivoted on respective sides of the lever eccentrically of the fulcrum of the lever. The bight portion 25 of the link is engaged in a reinforcing rib 24 on the back of the clamp member 16, its arms having such length that with the lever 22 extended downwardly as in Fig. 1 close against the hinge leaf 15, the clamp 18 will be drawn hard against the insulator 19 so as to close the channel 20 in the insulator at its upper part, whereby a wire 28 laid in the channel will be securely held therein and supported by the shank 11.

It should be noted that the bight portion 25 of the link is extended in bowed form substantially at right angles to the plane of the two arms of the link so as to afford a measure of resilient action when the link is put under stress by a closing operation of the lever 22.

The outer end of the lever is formed with a hook-like bill or enlargement 26 against which the hook of a pike or the like can be engaged to move the lever from release position shown in Fig. 3 to closed position shown in Fig. 4. In the latter position the connection of the link with the lever is slightly past dead center relation to the pivot of the lever, so that stress of the insulator proper 19 tending to open the device will serve to lock the lever in closing position, together with strain of the resilient link; yieldable however, to pressure of a pike or the like against its extremity tending to move it to the open position of Fig. 3.

At the upper edge of the clamp member 16, a projecting lip 27 is formed which may be used to assist in opening the device in case the sides of the channel 20 become stuck together, which might occur if some adhesive material should gain access thereto. Also, in case of a sleet storm, if ice sheaths the clamp and cross piece 14, the clamp may be forced open after movement of the lever 22 to open or released position, by using a pike or other pole device to break the ice in part, and then using a hooklike pole piece to pull the lip 27 outward and away from the cross piece 14.

it may be noted that the length of the lever 22 is such that it extends a distance below the hinge and knuckle portion of the base piece of the device, so that the end of the lever may be readily engaged to eifect its release by a simple pressure against its extremity tending to move it toward released position. By reason of the proximity of the link to dead center position, very little force is re quired to effect this initial movement, after which stress in the insulator 19 by which the latter reacts after deformation, will act to complete movement of the lever and the insulator to open positions shown in Fig. 3.

The insulator body projects at each end beyond the channelled parts 14 and 13, so that bending of a wire .2 supported in the device will be distributed over a considerable part of the wire longitudinally and liability to fatigue breakage minimized.

In the use of the device, the upper extremity of the shank being engaged through the crossarm and secured, a line wire may be laid by being lifted on a properly formed pike such as shown in Fig. 6, and laid in the channel while the device is in the condition shown in Fig. 3. A wire may be laid in one or a plurality of the insulators and initially tensioned or sagged, after which the clamps may be closed by pulling down on the ends of the levers 22 so as to move each of them to the closed position shown in Fig. 4.

In this device as heretofore used, the length of the cross member 14 and cross head or clamp 18 has been made about four inches, and the insulator proper 19 is made of sufiicient length to project about three quarters of an inch at each end. These proportions may be varied as experience and service requirements dictate but it has been found of considerable advantage to have a sufiicient length of wire engaged in the insulator and clamping means so that good sagging may be preserved without requiring the use of strain towers or positive fastenings to prevent development of irregular sagging in sleet and wind storms.

The present invention has the same utility explained for the device in my said copending application, and in addition requires only one movement to open the device for release and reception of a wire and one movement to effect the locking of the wire when laid and sagged.

Various forms of pikes or poles may be employed for effecting the operation of the lever as described. Equipment on fire apparatus and equipment in use by linemen generally may be used to effect the necessary opening and closing operations of the lever.

Due to its U-shape in cross section, the lever has two cheek plates 29 one at each side, joined by a bight portion 30 and constituting the major part of the lever. It may be noted that the fulcrum pin 31 on which the lever 22 is pivoted is located close to the inner side of the knuckle piece 17 in the reinforcing rib 24, and is engaged through the cheek plates 29 of the lever 22 near the inner sides or edges of the latter as it hangs in closed or clamping position shown in Fig. 4. The ends of the link-yoke 23 are pivoted to the lever at the far or outer side of the lever and the link is slightly below dead center in relation to the fulcrum as viewed in Fig. 4.

It should also be noted that the channel in the crosspiece 14 encircles the insulator 19 for nearly one-half is circumference, and also the channelled clamp 18 also encircles the insulator to such extent that there is a very small clearance between the clamp and cross piece 14 when the lever 22 is in closed position as in Figure 4. This insures very positive closing of the wire-holding channel 20 in the insulator 19, and also very positive frictional gripping of the wire in the clamped insulator, so that the insulator will resist adequately very powerful longitudinal pull on the wire. Proper sagging of the wire established by the lineman when stringing a line will thus be safely maintained, and liability of structural failures of the line by unequal axial stresses in different sections of the line greatly minimized.

The foregoing disclosure is exemplary, and it will be understood that various modifications of the specific structure shown and described may be made without departing from the spirit of the invention as expressed in the appended claims.

1 claim:

1. An insulator for communication lines and the like comprlsing a pendant base member constructed for en gagement with a cross arm support or the like and having a body portion arranged to extend from an engaged cross arm, said body portion including a channelled cross member open in a horizontal direction and a hinge leaf extended therebelow, a second hinge member pivoted at the extremity of the hinge leaf and having a complementary channelled cross-head clamp arranged to align with the cross member with the two channelled parts opposed, a substantially cylindrical deformable elastic insulator body having a longitudinal channel normally open at its upper side to receive a line wire freely, said elastic body engaged in the channel open upwardly, beside :said body portion, its outer side shaped to receive and fit the channel of said cross head, a lever pivoted on the said body portion to swing thereon opposite said second hinge member, a link pivoted to the second hinge member and to said lever eccentrically of the pivot of the lever on the body portion, the last named connection of the link with the lever being positioned to swing past a dead center position on closing movement of the lever and clamp to a closed position with said insulator body compressed between the cross member and cross head, said lever being shaped and arranged on its pivot so as to lie against the hinge leaf as a stop when in said closed position and having a length to extend a distance below the hinge leaf when in said closed position for engagement by a pole and the like for movement thereby toward open position to free said insulator so that the latter may move the clamp to an open position, and to open said channel in the insulator for placement and removal of a line wire.

2. The structure of claim 1 wherein said link is a substantially U-shaped resilient wire member having its arms at respective sides of the hinge leaf and second hinge member, its extremities being pivoted in one, and its bight portion pivotally engaged with the other of said hinge leaf and hinge member.

3. The structure of claim 2, wherein the bight of said link is tortile and constitutes a limited spring element having a strength initially overba'lancing the reactive force of the said insulator when the channel of the insulator is closed.

4. An insulator for field lines constructed for engagement with a support and having a pendant body including a channelled cross member, a hinge leaf extended in fixed relation to the cross member below the level of the channel therein, a second hinge member pivoted to the hinge leaf and having a complementary channelled crosshead clamp arranged to align with the cross member with the channel parts opposed, an elongated deformable elastic rubber-like insulator body set in one channel and fitted to the other, said insulator body having a longitudinal channel in its upper side normally open to a width to receive a line wire freely therein by vertical translation of the wire when said clamp is in open position, a lever pivoted on the said body opposite said second hinge member, a link pivoted to the second hinge member and to said lever eccentrically of the pivot of: the lever, said link lying below the cross member and cross head, said lever having an elevated open position, the connection of the link and lever being arranged on the latter so as to swing past a dead center position on closing movement of the lever and draw the clamp to a closed position clamping said insulator body to close said channel in the latter, said pendent body having a part positioned as a stop for the lever at closed position of the latter, and said lever having a length to extend a distance below all other parts of the insulator when in closed position, for engagement by a pole and the like and moved thereby toward open position to free said insulator body for placement and removal of a line wire.

Fry July 6, 1869 Edwards Nov. 24, 1908 

